Innumerable fish inhabit this sea.

What does this function represent?

He expresses numbers using numerals.

This index indicates the health of the economy.

I am drinking tea as a substitute for coffee.

The room rent is too high, so I'm looking for a new apartment.

When I was in my teens, I used to play soccer every day.

She is learning how to use pronouns.

I forgot to pay the bus fare.

The train fare is high, making my monthly expenses tough.